Hepatocellular carcinoma (HCC) is one of the most common cancers worldwide and its incidence is gradually increasing in Japan as well as in United States (Akriviadis E A, et al., Br J Surg. 1998 October; 85(10):1319-31). Recent medical advances have made great progress in diagnosis, a large number of patients with HCCs are still diagnosed at advanced stages and their complete cures from the disease remain difficult. In addition, patients with hepatic cirrhosis or chronic hepatitis have a high risk to HCCs, they may develop multiple liver tumors, or new tumors even after complete removal of initial tumors. Therefore development of highly effective chemotherapeutic drugs and preventive strategies are matters of pressing concern.